Rust-proofing iron, steel, or the like.



A. BONTEMPI.

RUST PROOPING IRON, STEEL, OR. THE LIKE. APPLIUATION FILED AUG. 11,-1911. BBNBWBD MAY 16. 1913.

1,072,904, Patented sept. 9, 1913. E

i Q. M l Hum/sro BQNTEMP/ l /w/G A i* isa/tram@ l entran stares serena* carica UGUSTO BON'l-EMlE-L 0F NEW YQBJK. N- Y, ASSIGNQR TQ BQNTEMH BUST PBQQFING UQMFANY, QORPORATIQN QF NEW YORK BUT-PROOHNG RON, STEEL,l *3R THE UKE- Specification of Letters Patent.

Patented Sept. 9, 1913.

Application leil August 11, 18,11, Serial No. 6%3,51. Renewed may 16, 1,913. Serial No. 768,158.

To all 'whom t may concern: j

Be it known that l, AUGUs'ro BONTEMPI, a subject of the King of Italy, and residmg in the city, county, and State of 'New York, have invented certain new and useful Improvements in Rust-Proofing Iron, Steel, or .the Like,` of which the following is a speeication,

This invention relates to the process of rust proofing metal surfaces and has for its object not only to expedite the process but also to protect the metal article treated from heat injury during the process.

in the rust proofing process hitherto de'- scribed by me in Patent 881,221, the temperature of the chamber in which the metal is placed during treatment is stated to be raised to from 1000@ F. to 18000 F. and the metal thus heated is subjected for several hours to the action of the fumes of suitable non-corrodible material which is fused and the fumes from which enter the pores of the highly heated metal as a gas and penetrate to a greater or less depth, serving on cooling to form a non-corrodible surface on the metal. The temperature of the article under treatment was kept high enough during treatment to insure the maintenance of the fumes of the non-corrodible material in gaseous condition during treatment. In practice it has been found that the maintenance of the article under treatment at a temperature sufliciently high for this purpose results frequently in serious injury to the article, and the utility of the process Was'thus llmited to articles of such character that the high temperature atv which they were `-kept in the treating chamber did not lnjuriously affect the same, While at the same time the duration of the treatment was pecpssarily prolonged to an undesirable exhave now found by further experimentation thatthe process'l is greatly expedited and the article under treatment safe-guarded against heat injury if its temperature be kept below that at which the rust proofing material fumes so that the fumes of the rust proofing material introduced into the treating chamber condense at once upon the article under treatment. At the same time, the article should be heated to such tem? perature that the pores of the vmetal are suitably-opened to receive the condensed material and preferably the article is heated to a sufficient temperature to maintain the condensed rust proofing material in fused oondition thereon during the continuance of the treatment. Upon cessation of the treatment and the cooling of the article, the rust proofing material hardens into a durable and efficient rust proofing surface, the thickness of which depends, of course, upon the length of the treatment. 1n ordinary cases the treatment is complete at the end of from half an hour to two hours treatment.

When treating iron the desired effect is obtained by heating the same to approximately from 900Q to 1.@00-j F. in a muilie chamber to which is led the fumes of a fused nnn-corrodible substance or compound which condense in fused condition at this temperature. The compounds used by me fume at a tem erature of approximately 1400o F. so

that t e fumes therefrom which are introduced into the treating chamber or munie at this temperature condense rapidly upon` the articles .therein Which are maintained at the lower temperature of 900 to 1200 F. Before subjecting the iron to the action of these fumes it may be treated with superheatedv steam, as I have previously suggested, and this is advantageous with heavy articles but may be entirely omitted without sensible loss of advantage in the case of light articles. There steam is employed, lime highly hygroscopic ma he introduced into the muiie to facilitate t e formation of the rust proofing surface by catalytic action. Naphtha or other hydrocarbon in small quantities may be injected With the steam to impart a black color to the surface.

A suitable apparatus for carrying out the invention is illustrated diagrammatically in the accompanying drawings, in which,

Figure 1 is a vertical section of the heating apparatus; and Fig. Q a sectional plan with the muliie removed.

In the form shown, Which may be variously modified without departing trom my inventiomthe apparatus comprises a muftle chamber 10 of lire-brick or other suitable refractory material, within which the article 11, which .is under treatment, is placed. This Inutile is heated to the required tempotatura by any suitable means, burners 12 being shown projecting into the space beneath the muille. The products of combustion passup around the ymuiie and escape at the outlet 13 at the top of the casing 14 of fire-brick and asbestos. Beneath thev Inutile and adjacent the burners I arrange for the sake of economy a steam box 15 in which the steam coming from any suitable source through the pipe 16 is super-'heated before introduction through the pipe 17 int-o the muifle chamber. Avalve 18 controls the inlet for the steam. On the opposite side of the furnace I have arranged a retort'19 in which are placed the substances comprising the rust proofing material. The latter is fused by the heat from the burners and the fumes pass up from the retort through the pipe 20 to t-he muiie chamber. A door 21 is provided for the retort chamber through which the chemicals may be introduced.

Where treatment by steam is not to be used in any particular case the articles to be treated are first heated by placing them in the muliie and starting the burners. As soon as a suitable temperature Vhas been secured in the muffle chamber the rust proong material is placed in the chemical retort, Where it is rapidly heated to a'temperature of 1400 F. or higher'y and the fumes rise from the fused material to the muftle chamber and rapidly condense upon the articles therein. If the'articles are to be first heated by steam, however, the cock 18 is' opened and the steam passing through the steam box 15 enters the muiiie chamber superheated to a temperature of 1400o F. or above. After the steam has been in contact with vthe articles a sufficient length of time, the cock 18 is closed andthe temperature of the chamber soon drops to 1200o F. or less. The chemicals are then introduced into the retort 19 and after the fumes thereof have filled the muiiie for the desired length of time, the

`a dark gray color; the second gives also a good coating a blue color, while the third gives a black coating of the very highest quality.

Before the treatment, the metal is washed perfectly clean, as usual, in rust prooing processes. After the goods are taken out of the muiie they are cooled to about 100 LF. and greased with vaseline and cleaned so as to give them a good polish and an attractive appearance.

I claim as my invention 1. The method of protecting iron or steel which comprises the step of subjecting the 'prising zinc, in a closed chamber, the tcmtially as described..

3. The method of protecting iron or steel which consists in subjecting the same to the action of steam and then subjecting the same to the action of the fumes of a fused, noncorrodible metalliferous substance in a closed chamber, the temperature of the article during the treatment thereof with said fumes being maintained above the `fusing and below the fuming temperature of said substance whereby a non-corrodible deposit is formed in a liquid state upon said article during treatment, substantially as described.

4. The method of protecting iron or steel which consists in subjecting the same to the action of steam and then subjecting the same to the action of the fumes of a fused, noncorrodible metalliferous substance, comprising zinc, in a closedchamber, the temperature of the article during the treatment thereof with said fumes being maintained above the fusing and belowT the fuming temperature of said substance whereby a noncorrodible deposit is formed in a liquid state upon said article during treatment, substantially as described.

In testimony whereof I have signed my name to this specification, in the preesncefof two subscribing witnesses.

AUGUSTO BONTEMPI.

Witnesses: H. D. LUCE,

WM. R. SWAN. 

